CA2884971A1

CA2884971A1 - Cutting device for agricultural machines

Info

Publication number: CA2884971A1
Application number: CA2884971A
Authority: CA
Inventors: Klemens Surmann; Dirk Webermann; Michael Pokriefke
Original assignee: Carl Geringhoff GmbH and Co KG
Current assignee: Carl Geringhoff GmbH and Co KG
Priority date: 2014-03-14
Filing date: 2015-03-13
Publication date: 2015-09-14
Anticipated expiration: 2035-03-13
Also published as: EP2918158A1; PL2918158T3; CA2884971C; US9357697B2; DE102014003493A1; BR102015005509B1; EP2918158B1; US20150305233A1; BR102015005509A2

Abstract

The present invention relates to a cutting device (2) for agricultural machines with several knife bar sections (4), which are driven so that they are at least temporarily movable in opposite directions and which extend over the working width of the cutting device (2), the knife blades (6) of which, at the time of a stroke movement of the knife bar sections (4), interact in a scissor-like manner with counter knives attached fixedly to the cutting device (2). In order to keep width of the unmown strip as small as possible or to completely avoid it, in the area of a gap (22) which results in the area of the mutually facing ends (8) of adjacent knife bar sections (4) as a result of the movement of the knife bar sections (4), and which becomes smaller and again larger continuously in accordance with the movement of the knife bar sections (4), a mowing finger (10) is arranged, next to which, in a transverse direction, cutting edges (16) of a knife blade (14) arranged fixedly in the area of this mowing finger (10) are formed, which extend at a slant relative to the forward travel direction (V) of the cutting device (2), so that the cutting edges (16) of this knife blade (14) have a V-shaped arrangement which broadens towards the forward travel direction (V), and, on the outer end faces of the outer knife blades (18), which are attached at the mutually facing ends (8) of adjacent knife bar sections (4), cutting edges (20) are formed, which extend parallel to the forward travel direction of the cutting device (2), wherein a drive (26) of the adjacent knife bar sections (4) has a phase offset of between 80° and 100°.

Description

Carl Geringhoff GmbH & Co. KG
Gersteinstr. 18 D - 59227 Ahlen Cutting Device for Agricultural Machines The present invention relates to a cutting device for agricultural machines with several knife bar sections, which are driven so that they are at least temporarily movable in opposite directions and which extend over the working width of the cutting device, the knife blades (6) of which, at the time of a stroke movement of the knife bar sections, interact in a scissor-like manner with counter knives attached fixedly to the cutting device.
A generic cutting device is known from the document DE 195 24 039 Al. The generic cutting devices can be used in particular with cutting devices for combine harvesters, but also in mowers for grass or for harvesting other agricultural stalk material.
In the document DE 195 24 039 Al, it is disclosed to subdivide a cutting device into at least two cutting device portions, in order to prevent oscillations and to avoid losses due to shaking. As a result of a phase shift of the driving frequency by 180 , the oscillation generated by one cutting device portion is supposed to be compensated by the other cutting device portion and, at best, eliminated. This results in the cutting device portions moving in opposite directions transversely to the working direction of the cutting device. In the case of a movement in opposite directions of the cutting device portions relative to one another, where said portions move apart from one another, a gap forms between them, which becomes larger in the course of the movement and which gradually closes only after the two external dead points have been reached in the subsequent backward movement and which is closed only for a short time when the two cutting device portions have reached their internal dead point. In the case of a phase shift by an amount other than than 180 , the gap is closed only for a brief time, alternatingly asymmetrically on the right and on the left. In the case of forward travel with the cutting device into an upright crop stand, an unmown strip representing an undesirable crop loss forms in the area of the gap.
The problem of the present invention is to keep the width of the unmown strip as small as possible or to prevent it entirely.
The problem is solved by a generic cutting device, by arranging a mowing finger in the area of a gap which forms in the area of the mutually facing ends of adjacent knife bar sections as a result of the movement of the knife bar sections and which becomes continuously smaller and larger again in accordance with the movement of the knife bar sections, and next to said mowing finger, in a transverse direction, cutting edges of a knife blade arranged fixedly in the area of this mowing finger are formed, which extend at a slant relative to the forward travel direction of the cutting device, so that the cutting edges of this knife blade have a V-shaped arrangement which broadens towards the forward travel direction, and, on the outer end faces of the outer knife blades, which are attached at the mutually facing ends of adjacent knife bar sections, cutting edges are formed, which extend parallel to the forward travel direction of the cutting device, wherein a drive of the adjacent knife bar sections has a phase offset of between 80 and 100 .
If the cutting device is provided with a finger mowing bar in which the mowing finger form the counter cutting edge, and the knife blades in the finger bar are guided so that they can move back and forth, the result is a clean cutting of the stalk material to be harvested, which consumes relatively little energy. A finger mowing bar is relatively insensitive to stones and

2 other obstacles, while requiring little maintenance, since there are only a few movable parts present. As a result of the mowing fingers attached to a finger mowing bar over the working width, it is possible, in particular, at the time of forward travel into the crop stand to lift stalk material lying on the ground with the mowing fingers, before it is cut. As a result, additional crop losses are avoided, which is of great significance, particularly in the case of a crop that is to be cut close to the ground, such as soybeans, for example.
As a result of this combination of the arrangement of knife blades and the formation of the cutting edges present on them, it is possible to bridge the gap, which forms due to the movement of the knife bar sections and which becomes smaller and again larger continuously in accordance with the movement of the knife bar sections, by means of the fixedly arranged knife blade. Here the cutting edges, which are arranged in the shape of a V. of the fixedly arranged knife blade work together in a scissor-like manner with the cutting edges of the outer knife blades attached on the mutually facing ends of adjacent knife bar sections, during their stroke movement toward the mowing finger arranged in the area of the gap, in order to be able to also reliably cut off the stalks of the crop present in the area of the fixedly arranged knife blade. In this manner, an unmown strip in the area of the gap between the knife bar sections is prevented.
In addition, the arrangement according to the invention also makes it possible, in the area of the gap and to the side thereof, to arrange mowing fingers which lift crops lying on the ground in the area of the gap and contribute to preventing crop losses by means of reliable cutting.
As a result of the phase offset in the drive of the adjacent knife bar sections of an order of magnitude between 80 and 1000, it is achieved that force peaks of the two knife bar sections occurring during the cutting of the stalk material occur with temporal offset, and the overall force required by the cutting device can be kept comparatively low as a result. In addition, in the case

3 of a given width of the knife blades and a resulting distance of the mowing fingers from one another, geometric conditions are produced wherein the gap between the knife bars is not excessively large and can be bridged by the stationary knife blade whose width corresponds at least approximately or exactly to the width of the remaining knife blades. The indicated phase offset of 800 to 1000 applies to a mechanical drive with rotating shafts relative to a complete 360 rotation of the drive shaft; in the case of a hydraulic or electronic control, the phase offset can also be implemented by hydraulic or electronic means.
According to an embodiment of the invention, the mowing finger arranged in the area of the gap is connected to two additional mowing fingers at a distance from the former mowing finger, via a common attachment bar, and the lateral distance between the two additional mowing fingers and the mowing finger arranged in the area of the gap corresponds in each case at most to the width of a knife blade moving in this interstice. The triple mowing finger formed in this manner forms a reliable guide for the mutually facing ends of the adjacent knife bar sections and the outer knife blades attached thereto during their stroke movements. As a result of the decrease in the distance between the mowing fingers to at most one knife blade width, said mowing fingers can satisfactorily support a knife blade moving in this area. The outer knife blades of the knife bar sections are supported during the stroke movement by the mowing fingers, and in this way they can perform a clean cut. In addition, the susceptibility to brittle failure decreases and the stability of the outer knife blades increases, when the outer knife blades have to absorb lower torsion forces due to the improved support.
According to an embodiment of the invention, the outer knife blades, which are attached at mutually facing ends of adjacent knife bar sections, in each case have a width which corresponds at least approximately to half the width of the remaining knife blades attached to a

4 knife bar section, and the knife blade, which is arranged fixedly in the area of the mowing finger arranged in the area of the gap, has a width which is at least approximately the width of the remaining knife blades attached to a knife bar section. As a result of the approximately halved width of the outer knife blades, one gets, in the case of an approximately trapezoidal base form of a whole knife blade, on the outer end face, a long straight cutting edge which works together with the associated cutting edge at the knife blade arranged fixedly in the area of the mowing finger, in order to cut stalk material, wherein the long cutting edge, in the course of a stroke movement, overlaps the entire associated cutting edge of the fixedly arranged knife blade, and, at least in an end position, is covered by a mowing finger arranged in the area of the gap.
According to an embodiment of the invention, two adjacent knife bar sections are provided with a drive which drives the two knife bar sections with phase offset. The term phase offset refers to a drive in which the knife bar sections are not movable at the same time in opposite directions or in the same direction. The drive can be produced, for example, by one or more cranks, push rods, eccentric shafts, a hydraulic cylinder or an electric motor. The phase offset can be produced by appropriate mechanical devices and/or by means of electrical, electronic or hydraulic switching devices. Due to the phase offset, it is achieved that the peak load on the drive train, which occurs when a position of the knife blades relative to the mowing finger as counter cutting edges is reached, always occurs only for one of two adjacent knife bar sections, so that the peak load is halved and temporally offset by the phase offset for the respective knife bar section located in the corresponding position. As a result, the drive train can be unburdened and designed to be more light weight.
According to an embodiment of the invention, two adjacent knife bar sections are driven by a rotating drive pulley whose rotation movement is transferred via connecting rods, which are connected eccentrically and with phase offset to the drive pulley, to rocker arms each of which is movable about swivel axles arranged approximately in the center and which are connected at their ends facing away from the connection with the associated connecting rod to the respective associated knife bar section. The drive of the two knife bar sections via a drive pulley establishes a good mechanical coupling and synchronization of the movements of the two knife bar sections.
The drive can be designed in a manner that saves space and is of lower weight, which is an important aspect in cutting systems.
According to an embodiment of the invention, the drive pulley and the connecting rods are mounted in a closed gear housing which is located on the lower side of the cutting device and behind the knife bar sections. As a result of the closed housing, the drive is maintenance-free.
Due to the improved protection against soiling, the drive has a longer useful life and is less susceptible to breakdown.
It is explicitly pointed out that the above described embodiments of the invention can in each case be combined separately but also any desired combination among one another with the subject matter of Claim 1.
Additional variants and designs of the invention can be obtained from the following concrete description and the drawings.
The invention will now be explained in further detail based on an embodiment example.
Figure 1 shows: a basic diagram of a cutting device, Figure 2 shows: the cutting device of Figure 1 with a modified position of the knife bar sections, and Figure 3 shows: the cutting device of Figure 1 with another modified position of the knife bar sections.

In Figure 1, a basic diagram of a cutting device 2 is shown. In the embodiment example 2, the cutting device has two knife bar sections 4, which are separated from one another in the central area of the drawing in the embodiment example. In the swivel position in which the knife bar sections 4 are located in Figure 1, the separation of the two knife bar sections 4 from one another is not visible, since they are submerged with their mutually facing ends 8 and the outer knife blades 18 attached thereto in the central mowing finger 10. In addition to the central mowing finger 10, which is located in the area of a gap 22 resulting during a movement of the knife bar sections 4, the cutting device 2 has several additional mowing fingers 12, which function as counter cutting edges for the knife blades 6 attached to the knife bar sections 4.
Beneath the mowing finger 10, a fixedly attached knife blade 14 is located, which is covered in Figure 1 by the outer knife blades 18. The stationary knife blade 14 has cutting edges 16 which extend at a slant relative to the forward travel direction V.
In the embodiment example, the mowing finger 10 is connected via a fastening strip 24 to adjacent mowing fingers 12, so that the three mowing fingers 10, 12 form a triple mowing finger component group. As a result of the supporting connection of the three mowing fingers via the fastening strip 24, the mowing finger 10 in particular is supported better against alternating stresses acting on it due to the movement of the two knife bar sections 4. The fastening strip 24 can be connected via screws, rivets or other fastening means to the cutting device 2.
In addition, in Figure 1, an embodiment example for a drive 26 is shown. The drive 26 starts from a rotating drive pulley 28 to which two connecting rods 30 are connected eccentrically. The two connecting rods 30 are movably connected at their ends facing away from the drive pulley 28 to rocker arms 32. In a rotation movement of the drive pulley 28, the connecting rods 30 push or pull the rocker arms 32 about the swivel axles 34 in accordance with the rotation position of the drive pulley 28 forward or backwards in a transverse direction of the cutting device 2. In Figure 1, the rotation movement of the drive pulley 28 is indicated by an arrow. The movement of the two knife bar sections 4, which is transferred at the time of a rotation of the drive pulley 28 in the direction of the arrow via the connecting rods 30 and rocker arms 32, is indicated by short arrows. Since the right connecting rod 30 has not yet reached its outermost dead point in the rotation position depicted in Figure 1, the right knife bar section 4 would still move a small distance towards the left in the case of an additional clockwise rotation of the drive pulley 28. In the case of a clockwise rotation of the drive pulley 28, the left connecting rod 30 would be pulled to the right, so that the left knife bar section 4 also moves to the left.
Figure 2 shows the cutting device 2 with a modified position of the knife bar sections 4.
The drive pulley 28 is rotated further by a small distance in comparison to the rotation position depicted in Figure 1, as a result of which the right connecting rod 30 has reached its right dead point in the transverse direction. In the case of an additional clockwise rotation of the drive pulley 28, the right knife bar section 4 would move to the right, induced by the rotation movement transferred via the connecting rod 30 and in the rocker arm 32. In the case of a continued clockwise rotation movement of the drive pulley 28, the left connecting rod 30 would be pulled farther to the right from the position shown in Figure 2, so that the left rocker arm 32 moves the left knife bar section 4 to the left.
In the rotation position of the drive pulley 28 shown in Figure 2, one can easily see that the outer knife blade 18 of the left knife bar section 4 has been moved away from the mowing finger 10 located in the area of the gap 22. The left outer knife blade 18, on its end face, has a cutting edge 20, which, at the time of a movement of the outer knife blade 18 toward the mowing finger 10, works together with the cutting edge 16 located on the knife blade 14, in order to cut off the stalk material located in this area of the cutting device 2. At the time of the travel of the outer knife blade 18 over the knife blade 14, a scissor-like cut results.
Since the outer knife blade 18 of the right knife bar section 4 is still located in the area of the mowing finger 10, the cutting edge 20 located on this outer knife blade 18 is still not visible in Figure 2. However, in this swivel position of the right knife bar section 4, one can see the cutting edge 16 of the knife blade 14 located there.
In Figure 3, the two knife bar sections 4 are shown close to their outermost dead point, so that the gap 22 between the two outer knife blades 18 can be seen easily.
While, during a continued clockwise rotation of the drive pulley 28, the left knife bar section 4 is already moved again in the direction of the mowing finger 10, the right knife bar section 4 continues to move a small distance away from the mowing finger 10, before it starts to run backward again. In order to be able to better represent the stationary knife blade 14, the mowing finger 10 is not shown in Figure 3. In Figure 3, one can easily see that the stalk material which is located in the area of the gap 22 between the cutting edges 16 and 20 of the stationary knife blade 14 and the two outer knife blades 18, is reliably cut at the time of the backward movement of the two knife bar sections 4 onto the mowing finger 10.
The invention is not limited to the above embodiment example. It is not difficult for the person skilled in the art to modify the embodiment example in a manner that appears suitable to him in order to adapt it to a concrete application case.

Claims

1. Cutting device (2) for agricultural machines with several knife bar sections (4), which are driven so that they are at least temporarily movable in opposite directions and which extend over the working width of the cutting device (2), the knife blades (6) of which, at the time of a stroke movement of the knife bar sections (4), interact in a scissor-like manner with counter knives attached fixedly to the cutting device (2), characterized in that, in the area of a gap (22) which results in the area of the mutually facing ends (8) of adjacent knife bar sections (4) as a result of the movement of the knife bar sections (4), and which becomes smaller and again larger continuously in accordance with the movement of the knife bar sections (4), a mowing finger (10) is arranged, next to which, in a transverse direction, cutting edges (16) of a knife blade (14) arranged fixedly in the area of this mowing finger (10) are formed, which extend at a slant relative to the forward travel direction (V) of the cutting device (2), so that the cutting edges (16) of this knife blade (14) have a V-shaped arrangement which broadens towards the forward travel direction (V), and, on the outer end faces of the outer knife blades (18), which are attached at the mutually facing ends (8) of adjacent knife bar sections (4), cutting edges (20) are formed, which extend parallel to the forward travel direction of the cutting device (2), wherein a drive (26) of the adjacent knife bar sections (4) has a phase offset of between 80 and 100 .

2. Cutting device (2) according to Claim 1, characterized in that the mowing finger (10) arranged in the area of the gap (22) is connected to two additional mowing fingers (12) arranged at a distance from said mowing finger via a common fastening strip (24), and the lateral distance between the two additional mowing fingers (12) and the mowing finger (10) arranged in the area of the gap (22) in each case corresponds at least to the width of a knife blade (18) moving in this interstice.

3. Cutting device (2) according to Claim 2, characterized in that the outer knife blades (18), which are attached on the mutually facing ends (8) of adjacent knife bar sections (4), in each case have a width which corresponds approximately to half of the width of the remaining knife blades (6) attached on a knife bar section (4), and the knife blade (14) which is arranged fixedly in the area of the mowing finger (10) arranged in the area of the gap (22) has a width which corresponds at least approximately to the width of the remaining knife blades (6) attached on a knife bar section (4).

4. Cutting device (2) according to any one of the preceding claims, characterized in that two adjacent knife bar sections (4) are provided with a drive (26) which drives the two knife bar sections (4) with phase offset.

5. Cutting device (2) according to Claim 4, characterized in that two adjacent knife bar sections (4) are rotated by a drive pulley (28) whose rotation movement is transferred via connecting rods (30), which are connected eccentrically and with phase offset to the drive pulley, to rocker arms (32) each of which is movable about swivel axles (34) arranged approximately in the center and which are connected at their ends (8) facing away from the connection with the associated connecting rod (30) to the respective associated knife bar section (4).

6. Cutting device (2) according to Claim 5, characterized in that the drive pulley (28) and the connecting rods (30) are mounted in a closed gear housing which is located on the lower side of the cutting device (2) and behind the knife bar sections (4).